Spark plug



` which thelfollowing is a speci Patented Mar. 3, 192.5.

UNITED STATES PATENT OFFICE.

EARL A. HASTINGS, OF QUIMBY, VIRGINIA..

erm PLUG.

Application led March 7, 1923. 'Serial'Nm 623,509.

.efficiently under all conditions and not become clogged up or corroded.y

Anotherobject of the invention is to provide a spark plug having a novelcentral electrode, which through its peculiar foi-ination insures a hotbig spark for firing the charge and prevents the forming of ycarbondeposits thereon.

A further object of the invention is to provide an improved lcentralelectrode for spark plugs embodying the usual conducting wire, .which iscoated with an alloy of platinum and mercury and then tightly woundwith, copper wire, and finally pro- 4vided `with a plastic coating of analloy of mercury, zinc, lead and tin,- the copper wire serving as agoodcronductor for heat for insuring the heating of the wire, and theplastic coating of the alloy of mercury, zinc, lead and tin, whichserves to intensify the spark by heating the wire.

A Vstill further objectfof the invention is to provide an improved sparkplu'g of the above character, which will be durable and efficient inuse', one that will be simple and easy to manufacture, and one which canbe placed upon the market at a reasonable cost. Y

With these and other objects in view, the invention consists in thenovel construction, arrangement and formation of parts, as will behereinafter more specifically described, claimed and illustrated in theaccompanying drawings, forming a part of this specification, in whichdrawings:

Figure 1 is a side elevation of the improved central electrode forspark. plugs showing the outer coating therefor in seotion.

` A line 3 3 of Figure 1, and

Figure 2 is a transverse section through the im roved electrode takenon'the line 2-2 o Figure 1.

Figure 3 is a similar section vtaken on the Figure 4 is an enlargedfragmentary ower tail longitudinal section through the end oftheelectrode showing the construeQ tion thereof.

Referring to the drawings indetail, wherein similar reference charactersdesignate corresponding parts throughout the several views the letter Agenerally indicates the improved electrode, which is sealed within anvordinary body of insulation or porcelain and the porcelain is thensecured to steel jacket of the spark plug in the ordma manner.

This electrode A embodies a central metal rod 5 or wire of the desiredage. The rod or wire 5 is of course forme Aof good electric conductingmaterial and has the upper end thereof threaded as at 6, for thereception of a retaining nut and washer 7 and 8, it beine' obvious thatthe nut and washer is utilize cury.

After the rod 5 is coated, a thin copper wire is wound tightly aroundthe saine as at 9, and it can be seen by referringl to Figure 1 of thedrawings that the windings increase from the opposite ends of the rod,

toward a point v'near the lower end of the rod. At the point where thewindings increase andmeet, the wire is-wound to form a stop shoulder 10for engaging the. lower end of the porcelain.

The rtion of the windings 9 above the shoulder 10 is then coated with analloy of'platinum, mercury, lead, tin and zinc 12 for a purpose, whichwill be hereinafter more fully described. These metals are combinedtogether in any preferred method and are of a plastic consistency, whichycan be readily spread on the copper windings by the lingers.'y

If so desired a suitable sleeve or ferrule 11 can be slipped on thelower end of the rod 5 and secured thereto in any preferred manner, soas to prevent copper wire from becoming unwound and from slipping 0E ofthe lower end of the rod. This of course is not vital to the invention.It is also preferred to solder the nut 7 on the rod 5 as at 12, whichalso aids i'n the intensifying of the spark.

The mercury in the alloy serves as a vehicle for the other metals andwhen the other metals are added theretothe alloy assumes I a semi-liquidor-pasty form, which as stated".

a good conductor of electricity and also hav-v mg a lowboilingppintfa'lso helps to keep the alloyl in a semi-liquid or. paste formupon cooling. The zinc also hel s to heat the electrode, which helps tofire t e charge. The lower winding of the copper on the rod 5 acts 'inthe nature of a heate'r or accumulator, and it is obvious that as copperis a good conductor of heat, the same will store up the heat and tend toheat the rod. The electrode will, under al1 conditions, burn itself freeof any oil, grease or carbon and will not short circuit even when vwateris poured on a plug. c

Changes in details may be made Without departing from the spirit or thescope of this.

v invention.

What I claim is 1. A central electrode for spark plugs comprising a rodof conducting material,a copper wire coiled about the rod, a plastic'alloy of mercury, zinc, lead and tin placed on the copper Wire startingat a point above the mercury, a copper Wire coiled about said v coatedrod, and a plastic coating of mercury, zinc, and lea-d placed upon theWire and terminating short of the upperand lower-ends thereof, thecopper Wire being wound a greater number of turns about the rod adjacentto the lower end thereof' to form a stop shoulder.

In testimonywhereof I aix my signature in presence of two Witnesses. f

l EARL Jfi.,HASTINGS,

Witnesses: Y l i W. L. GLADDEN,

P. C. AYREs.

